The Battle of Koromo River took place during the opening years of the

Kamakura period The is a period of Japanese history that marks the governance by the Kamakura shogunate, officially established in 1192 in Kamakura by the first ''shōgun'' Minamoto no Yoritomo after the conclusion of the Genpei War, which saw the struggle bet ...

(12th century) of Japan. After the destruction of the Heike,

Minamoto no Yoshitsune was a military commander of the Minamoto clan of Japan in the late Heian and early Kamakura periods. During the Genpei War, he led a series of battles which toppled the Ise-Heishi branch of the Taira clan, helping his half-brother Yoritomo conso ...

conflicted with his brother

Minamoto no Yoritomo was the founder and the first shogun of the Kamakura shogunate of Japan, ruling from 1192 until 1199.Nussbaum, Louis-Frédéric. (2005). "Minamoto no Yoriie" in . He was the husband of Hōjō Masako who acted as regent (''shikken'') after his ...

, and fled into

Hiraizumi is a town located in Nishiiwai District, Iwate Prefecture, Japan. , the town had an estimated population of 7,408 and a population density of in 2,616 households. The total area of the town was . It is noted for the Historic Monuments and Sit ...

, Mutsu Province. He was sheltered by Northern Fujiwara's 3rd ruler

Fujiwara no Hidehira was the third ruler of Northern Fujiwara in Mutsu Province, Japan, the grandson of Fujiwara no Kiyohira. During the Genpei War, he controlled his territory independently of the central government; however, he was the official imperial governor f ...

. Hidehira appointed Yoshitsune as general to be opposed to Yoritomo, but he died of illness on October 29, 1187. Yoritomo strongly pressured

Fujiwara no Yasuhira was the fourth ruler of Northern Fujiwara in Mutsu Province, Japan, the second son of Hidehira. At first protecting Yoshitsune, according to his father's will, he was finally forced by Minamoto no Yoritomo to attack Yoshitsune. Yoshitsune, rat ...

, the 2nd son and successor of Hidehira, through the Imperial Court to arrest Yoshitsune. Against the will of his father, Yasuhira succumbed to the repeated pressure of Yoritomo. On June 15, 1189, he led 500 soldiers to attack Yoshitsune and an entourage of servants in the Koromogawa no tachi residence. Yasuhira defeated Yoshitsune and his compatriot, Saitō no Musashibō Benkei. Throughout the battle, Benkei defended his lord. Benkei supposedly died standing up, which caused great fear in his enemies. Yoshitsune himself committed suicide at the end of the battle.

References

1180s in Japan 1189 in Asia Koromo River Koromo River {{Japan-battle-stub